1. Field of the Invention
This invention relates to a mobile radiotelephone station set, sometimes called a control unit. The invention more particularly relates to a station set that has in a base portion both subscriber operated controls and a directory facility for listing frequently called numbers.
2. Prior Art
Telephone users often keep close to their telephone a list of frequently called numbers. Such a list is particularly useful in mobile radiotelephone operation because the subscriber may not have a directory in his vehicle or it may be inconvenient to use a regular directory while the motor vehicle is briefly stopped in traffic. Directory lists for frequently called numbers can, of course, be attached to a blank space on the face of a telephone station set. However, there is usually insufficient space available on a set to record a significant number of telephone numbers if the recorded items are to be of a suitably legible size. A separate larger list could also be loosely attached to a station set, but in a mobile environment such a list is likely to swing back and forth and constitute an annoying diversion to a driver during normal motor vehicle operation.
There are, of course, other ways known in the art for providing directory lists of frequently called numbers at telephone station sets. One such arrangement involves a directory pad which is contained in a small drawer in an auxiliary base member to which the station set base is secured. Alternatively, it is known in the prior art to list frequently called numbers on a strip of paper that is wound on a roller which is attached in a mechanism secured to the outside of the station set. Both such arrangements are somewhat awkward and are obviously inconvenient for mobile radiotelephone operation because, for example, it is difficult with either arrangement to achieve a stable indexing of selected number in a way in which it is readily readable by the vehicle driver and which indexing is automatically retained in spite of vibrations and possible substantial vehicle accelerations in any direction.
Aside from questions of convenience, a mobile radiotelephone must be so configured as to be capable of unobtrusive mounting in a motor vehicle near the driver of the vehicle, and it must be so mountable in all sizes and kinds of vehicles. Thus, a cardinal principle of mobile radiotelephone station set design, and often also of fixed station set design, is to keep the station set to a small size so that the range of possible mounting locations is as large as possible. However, the requirement for a small size conflicts with the desire of many users to have user controlled and user advisory elements of the station set in a single compact location but still easily seen and operated. It particularly conflicts with driver convenience in terms of directory listings of frequently called numbers and in terms of other related aspects such as dialing arrangements, handset hanging arrangements, and arrangements for illuminating station set controls during nighttime operation.
It is, therefore, one object of the invention to improve telephone station sets, particularly those adapted for mobile radiotelephone service.
It is another object to group the principal user controlled and user advisory elements of a station set in a base portion thereof of relatively small size and including at least built-in facilities for dialing numbers and for listing frequently called numbers.
It is another object to locate a directory listing of readily readable size and of conveniently large capacity within a telephone station set containing a conventionally sized pushbutton dialing arrangement.